up fresh power, and we had accumulated a supply amply
sufficient to meet any extra requirements in the event of our arrival
upon Mars being unduly delayed.

We now turned and looked back at the earth; and, as the moon was so near
to it at that time, the earth's disc appeared very nearly two degrees in
diameter, or nearly four times the usual apparent diameter of the full
moon as seen from the earth. The crescent of light on its right-hand
side was rather wider than when we last looked at it; but so many clouds
hung over it, that we could not see what countries were comprised in the
lighted portion of its surface. Owing to the light of the stars behind
the earth being diffused by the dense atmosphere--in the same way as it
would be diffused by a large lens--there was a ring of brilliant light
like a halo all round the earth's disc.

Having passed away from the moon, I now gave M'Allister the necessary
directions in order to keep the _Areonal_ on a course which would enable
us to head off the planet Mars at, as near as I could reckon, the point
it would reach in fifty days' time. The course having been set,
M'Allister was free to join us again, as the machinery required very
little attention.

When he did so, M'Allister at once asked me a question. "Professor, can
you tell me when it's going to be daylight? The sun has been shining for
hours and hours, yet it's still night; the sky is blacker than the
blackest night I ever saw, and the stars are all out!"

John laughed heartily, and said, "M'Allister, this is daylight! and all
the daylight you will get until we reach Mars."

M'Allister turned to me with a perplexed look on his face and asked, "Is
that right, Professor, or is he trying to pull my leg, as he said he
would?"

"Oh yes! It's quite right, M'Allister," I replied. "It is now full
daylight, and we shall have no more night until we reach Mars. That, as
you know, will be seven weeks from the present time."

"Well, Professor," he exclaimed, "then how is it the sky is so densely
black and the stars all shining so brightly? I never saw the stars in
the daytime before, yet these are shining brighter than they do on the
earth at night."

"Simply," I said, "because upon the earth we were surrounded by a dense
atmosphere, which so diffused the sun's light that the whole sky
appeared bright. The stars were there all the time, but their light was
so overpowered by the brilliancy of the atmosphere that they were quit